Lens module

ABSTRACT

A lens module includes a barrel, a first lens, a second lens, and a spacer. The first lens and the second lens are received in the barrel from an object side to an image side of the lens module. Each lens includes an optical portion and a non-optical portion around the optical portion. The spacer is positioned between the non-optical portion of the first lens and the non-optical portion of the second lens. The second lens includes an image-side surface. The non-optical portion on the image-side surface includes a contact portion. The contact portion defines a triangular notch.

BACKGROUND

1. Technical Field

The present disclosure relates to a lens module.

2. Description of Related Art

Plastic lenses are less expensive than glass lenses, therefore plasticlenses are popular in lens modules. However, the optical quality of theplastic lenses is worse than that of the glass lenses. Such as, when alight source (such as an electronic light) irradiates the lens modulehaving plastic lenses, the captured image will have many kinds ofastigmatism.

Therefore, it is desirable to provide a lens module that can overcomethe above-mentioned limitations.

BRIEF DESCRIPTION OF THE DRAWINGS

Many aspects of the embodiments should be better understood withreference to the following drawings. The components in the drawings arenot necessarily drawn to scale, the emphasis instead being placed uponclearly illustrating the principles of the present disclosure. Moreover,in the drawings, like reference numerals designate corresponding partsthroughout the several views.

FIG. 1 is a schematic, cross-sectional view of a lens module, accordingto an exemplary embodiment, the lens module including a first lens, asecond lens, a third lens, a fourth lens and a fifth lens.

FIG. 2 is a schematic, cross-sectional view of half of the second lensof the lens module of FIG. 1.

FIG. 3 is a schematic, cross-sectional view of half of the fifth lens ofthe lens module of FIG. 1.

DETAILED DESCRIPTION

Referring to FIG. 1, a lens module 100, according to an embodiment,includes a barrel 101, a first lens 11, a second lens 12, a third lens13, a fourth lens 14, a fifth lens 15, five spacers 20, and an imagesensor 30.

The barrel 101 is cylindrical, and includes a semi-enclosed object end102, an image end 103, and a receiving space 104 communicating betweenthe object end 102 and the image end 103. In one exemplary embodiment,the inner diameter of the image end 103 is D, and D is equal to about5.3 millimeter (mm).

The five lenses 11-15 are received in the receiving space 104 along anoptical axis M of the lens module 100 from the object end 102 to theimage end 103. Each of the five lenses 11-15 has an optical portion forimaging and a non-optical portion around the optical portion. Each ofthe five lenses 11-15 further has an object-side surface facing theobject side of the lens module 100 and an image-side surface facing theimage side of the lens module 100. When capturing an image, incidentlight rays enter the lens module 100, transmit through the five lenses11-15, and reach the image sensor 30.

The five spacers 20 are made of elastic material, and received in thereceiving space 104. Four of the five spacers 20 are each interposedbetween the non-optical portions of two adjacent lenses. The remainderone of the five spacers 20 is positioned on the image-side surface ofthe fifth lens 15.

Also referring to FIG. 2, the non-optical portion of the second lens 12includes a first contact portion 121 on the image-side surface of thesecond lens 12. The first contact portion 121 is adjacent to the opticalportion and abuts against the corresponding spacer 20. The first contactportion 121 defines a triangular first notch 122, the length of theopening of the first notch 122 is L1, 0.2 mm≦L1≦0.5 mm, and thus0.0377≦L1/D≦0.0943. The first notch 122 surrounds the optical portion ofthe second lens 12. The first notch 122 has an apex angle θ1 facing thecorresponding spacer 20, 120°≦θ1≦170°. The distance from an apex A ofthe apex angle θ1 to the optical axis of the lens module 100 is D1, 1mm≦D1≦5 mm, and thus 0.189≦D1/D≦0.943. The distance from the apex A tothe first contact portion 121 along the optical axis of the lens module100 is D2, that is, D2 is the depth of the first notch 122, 0.01mm≦D2≦0.05 mm, and thus 0.002≦D2/D≦0.009. In one exemplary embodiment,L1 is about 0.16 mm, θ1 is about 124°, D1 is about 1.39 mm, D2 is about0.05 mm. Thus, when the angle between the light source and the opticalaxis of the lens module 100 is about 45°, the falcate astigmatism on theimage of the light source can be reduced.

The non-optical portion of the second lens 12 includes a second contactportion 125, a third contact portion 126, and a connecting portion 127connecting the second contact portion 125 and the third contact portion126. The second contact portion 125, the third contact portion 126, andthe connecting portion 127 are on the image-side surface of the secondlens 12. The second contact portion 125 abuts against the inner sidewallof the barrel 101. The third contact portion 126 abuts against the thirdlens 13. The connecting portion 127 has an inclined surface 129. Theincluded angle between the inclined surface 129 and the optical axis ofthe lens module 100 is θ2, 100°≦θ2≦160°. The inclined surface 129 has afirst end 129 a and a second end 129 b. The first end 129 a is away fromthe optical axis of the lens module 100 in relative to the second end129 b. The distance between the first end 129 a and the optical axis ofthe lens module 100 is D3, 2 mm≦D3≦2.5 mm, and thus 0.377≦D3/D≦0.472.The distance between the second end 129 b and the optical axis of thelens module 100 is D4, 1.8 mm≦D4≦2.4 mm, and thus 0.339≦D4/D≦0.453. Inone exemplary embodiment, θ2 is about 135°, D3 is about 2.32 mm, D4 isabout 2.15 mm.

Thus, when the angle between the light source and the optical axis ofthe lens module 100 is about 46°, the blade-shaped astigmatism on theimage of the light source can be eliminated. When the angle between thelight source and the optical axis of the lens module 100 is about 52°,the falcate astigmatism on the image of the light source can beeliminated.

Also referring to FIG. 3, the object-side surface of the fifth lens 15has a fourth contact portion 151 abutting against the correspondingspacer 20. The fourth contact portion 151 defines a triangular secondnotch 152. The second notch 152 surrounds the optical portion of thefifth lens 15. The length of an opening of the second notch 152 alongthe direction perpendicular to the optical axis of the lens module 100is L2, 0.1 mm≦L2≦0.5 mm, and thus 0.019≦L2/D≦0.094. The second notch 152has an apex angle θ3 facing the corresponding spacer 20, 120°≦θ3≦170°.The distance from the apex B of the second notch 152 to the optical axisof the lens module 100 is D5, 1.7 mm≦D5≦2.3 mm, 0.321≦D5/D≦0.434. Thedistance from the apex B of the second notch 152 to the fourth contactportion 151 is D6, that is, D6 is the depth of the second notch 152, 0.1mm≦D6≦0.5 mm, and thus 0.019≦D6/D≦0.094. In one exemplary embodiment, L2is about 0.15 mm, θ3 is about 124°, D5 is about 2 mm, D6 is about 0.18mm. Thus, when the angle between the light source and the optical axisof the lens module 100 is about 36°, the astigmatism on the image of thelight source can be reduced.

The non-optical portion on the image-side surface of the fifth lens 15has a spaced portion 150. The spaced portion 150 is adjacent to theoptical portion of the fifth lens 15 and not in contact with thecorresponding spacer 20. The spaced portion 150 defines an arc-shapedgroove 156. The groove 156 surrounds the optical portion of the fifthlens 15. The radius of the groove 156 is R1, 0.03 mm≦R1≦3 mm, and thus0.006≦R1/D≦0.566. The length of the opening of the groove 156 along adirection perpendicular to the optical axis of the lens module 100 isL3, 0.1 mm≦L3≦0.5 mm, and thus 0.019≦L3/D≦0.094. The distance from theend of the groove 156 adjacent to the optical portion to the opticalaxis of the lens module 100 is D7, 2 mm≦D7≦2.6 mm, and thus0.377≦D7/D≦0.491. In one exemplary embodiment, R1 is about 0.1 mm, L3 isabout 0.15 mm, D7 is about 2.26 mm. The inner surface of the groove 156is nebulized, and thus, when the angle between the light source and theoptical axis of the lens module 100 is about 36°, the astigmatism on theimage of the light source can be eliminated.

It will be understood that the above particular embodiments are shownand described by way of illustration only. The principles and thefeatures of the present disclosure may be employed in various andnumerous embodiments thereof without departing from the scope of thedisclosure as claimed. The above-described embodiments illustrate thescope of the disclosure but do not restrict the scope of the disclosure.

1. A lens module comprising: a barrel having a semi-enclosed object endand an image end, the barrel defining a receiving space communicatingbetween the object end and the image end; a first lens; a second lens;and a first spacer; wherein the first lens, the first spacer and thesecond lens are received in the receiving space in an order from anobject side to an image side of the lens module, each of the first lensand the second lens comprises an optical portion and a non-opticalportion around the optical portion, the first space is positionedbetween and contacts the non-optical portion of the first lens and thenon-optical portion of the second lens, the second lens comprises animage-side surface, the non-optical portion on the image-side surfacecomprises a first contact portion, the first contact portion defines atriangular first notch surrounding the optical portion of the secondlens.
 2. The lens module of claim 1, wherein the first notch has anopening, a length of the opening is L1, the image end has an innerdiameter D, 0.0377≦L1/D≦0.0943.
 3. The lens module of claim 2, whereinthe first notch has an apex angle θ1 facing the image end, 120°≦θ1≦170°.4. The lens module of claim 3, wherein a distance from an apex of theapex angle θ1 to an optical axis of the lens module is D1,0.189≦D1/D≦0.943, a depth of the first notch is D2, 0.002≦D2/D≦0.009. 5.The lens module of claim 2, wherein the lens module further comprises athird lens on an image side of the second lens, the non-optical portionof the second lens comprises a second contact portion, a third contactportion, and a connecting portion connecting between the second contactportion and the third contact portion, the second contact portion abutsagainst an inner sidewall of the barrel, the third contact portion abutsagainst the third lens, the connecting portion comprises an inclinedsurface, an included angle between the inclined surface and the opticalaxis of the lens module is θ2, 100°≦θ2≦160°.
 6. The lens module of claim5, wherein the inclined surface comprises a first end and a second end,the first end is positioned away from the optical axis of the lensmodule relative to the second end, a distance between the first end andthe optical axis of the lens module is D3, 0.377≦D3/D≦0.472, a distancebetween the second end and the optical axis of the lens module is D4,0.339≦D4/D≦0.453.
 7. The lens module of claim 2, wherein the lens modulecomprises a third lens, a fourth lens, and a fifth lens, all of whichare positioned on the image side of the second lens in an order from theobject side to the image side of the lens module, the lens modulefurther comprises a second spacer, a third spacer, a fourth spacer, eachof the second, third and fourth spacers is positioned between each twoadjacent lenses of the second, third, fourth and fifth lenses, the firstcontact portion contacts the second spacer, the fifth lens comprises anoptical portion and a non-optical portion around the optical portion,the non-optical portion of the fifth lens comprises a fourth contactportion on an object-side surface of the fifth lens, the fourth contactportion abuts against the fourth spacer, the fourth contact portiondefines a triangular second notch surrounding the optical portion of thefifth lens.
 8. The lens module of claim 7, wherein the second notch hasan opening, a length of the opening of the second notch along adirection perpendicular to the optical axis of the lens module is L2,0.019≦L2/D≦0.094, the second notch comprises an apex angle θ3 facing thefourth spacer, 120°≦θ3≦170°, a distance from the apex of the apex angleto the optical axis of the lens module is D5, 0.321≦D5/D≦0.434, a depthof the second notch is D6, 0.019≦D6/D≦0.094.
 9. The lens module of claim7, wherein the lens module comprises a fifth spacer positioned on animage-side surface of the fifth lens, the non-optical portion on theimage-side surface of the fifth lens has a spaced portion, the spacedportion is adjacent to the optical portion of the fifth lens andseparates from the fifth spacer, the spaced portion defines anarc-shaped groove surrounding the optical portion of the fifth lens, aninner surface of the arc-shaped groove is nebulized.
 10. The lens moduleof claim 9, wherein a radius of the arc-shaped groove is R1,0.006≦R1/D≦0.566, a length of the opening of the arc-shaped groove alonga direction perpendicular to the optical axis of the lens module is L3,0.019≦L3/D≦0.094, a distance from an end of the arc-shaped grooveadjacent to the optical portion of the fifth lens to the optical axis ofthe lens module is D7, 2 mm≦D7≦2.6 mm.